Gallbladder Metastasis from Renal Cell Carcinoma.

We experienced a rare case of gallbladder metastasis from renal cell carcinoma. A 68-year-old man was admitted for further evaluation of a gallbladder tumor, which had been identified on follow-up computed tomography after partial nephrectomy for renal cell carcinoma. Enhanced computed tomography and magnetic resonance imaging showed an enhancing polypoid mass in the gallbladder lumen. Endoscopic ultrasonography demonstrated a homogenous hypo-echoic polypoid lesion, and the outer hyper-echoic layer of the adjacent wall was intact. Blood flow signals in the wall side of the mass were observed on color Doppler endoscopic ultrasonography images. Laparoscopic cholecystectomy was performed and he was uneventfully discharged. Macroscopic examination of the specimen revealed a 12 × 7 × 5 mm pedunculated tumor attached by a thin pedicle to the fundus of the gallbladder. Histology confirmed a metastasis of the renal cell carcinoma that had infiltrated the shallow subserosa but had mainly grown into cavity of the gallbladder. These imaging findings are considered characteristic and may assist preoperative diagnosis in patients with a history of renal cell carcinoma.